Orbital Interactions in Bi‐Sn Bimetallic Electrocatalysts for Highly Selective Electrochemical CO2 Reduction toward Formate Production. Issue 31 (21st September 2018)

• Record Type: Journal Article
• Authors: Wen, Guobin; Lee, Dong Un; Ren, Bohua; Hassan, Fathy M.; Jiang, Gaopeng; Cano, Zachary P.; Gostick, Jeff; Croiset, Eric; Bai, Zhengyu; Yang, Lin; Chen, Zhongwei
• Is Part Of: Advanced energy materials. Volume 8:Issue 31(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-21
• Subjects: bimetallic -- carbon dioxide reduction -- DFT calculations -- electrocatalysts -- formate; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201802427
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: A highly selective and durable electrocatalyst for carbon dioxide (CO2 ) conversion to formate is developed, consisting of tin (Sn) nanosheets decorated with bismuth (Bi) nanoparticles. Owing to the formation of active sites through favorable orbital interactions at the Sn‐Bi interface, the Bi‐Sn bimetallic catalyst converts CO2 to formate with a remarkably high Faradaic efficiency (96%) and production rate (0.74 mmol h −1 cm −2 ) at −1.1 V versus reversible hydrogen electrode. Additionally, the catalyst maintains its initial efficiency over an unprecedented 100 h of operation. Density functional theory reveals that the addition of Bi nanoparticles upshifts the electron states of Sn away from the Fermi level, allowing the HCOO* intermediate to favorably adsorb onto the Bi‐Sn interface compared to a pure Sn surface. This effectively facilitates the flow of electrons to promote selective and durable conversion of CO2 to formate. This study provides sub‐atomic level insights and a general methodology for bimetallic catalyst developments and surface engineering for highly selective CO2 electroreduction. Abstract : Orbital interactions of Bi‐Sn lead to the electrocatalytic conversion of CO2 to formate with high selectivity, activity, and durability. This is attributed to the electronic states of Sn upshifting away from the Fermi level due to the coupling with Bi, making the HCOO* intermediate adsorb more favorably on Bi‐Sn than on pure Sn surfaces.